Best way to travel between Lisbon and Helsinki

A: Lisbon

B: Helsinki

Travel Modes: Price; Distance; Duration; CO2

flight: $262.0; 3495.82 km; 7h 50mins; 377.55 kgs

train: $356.0; 5022.15 km; 101h 41mins; 266.17 kgs

bus: $368.0; 6121.5 km; 109h 16mins; 183.64 kgs

drive: $950.0; 4900.74 km; 56h 10mins; 627.29 kgs

Tranport	Distance	Time(hrs)	Cost(local)	Cost(usd)
Flight	3495.82 km	7h 50mins	193 EUR	262.0
Train	5022.15 km	101h 41mins	262 EUR	356.0
Bus	6121.5 km	109h 16mins	271 EUR	368.0
Drive	4900.74 km	56h 10mins	700 EUR	950.0

Take Train from Rossio to Alameda: Time: 7mins Cost: 1 EUR; $ 1.8 - 2.2 USD CO2 Emission: 0.14 kgs
Take Train from Alameda to Lisbon airport: Time: 19mins Cost: 1 EUR; $ 1.8 - 2.2 USD CO2 Emission: 0.44 kgs
Take Flight from LIS to HEL: Time: 4h 43mins Cost: 184 EUR; $ 225.0 - 275.0 USD CO2 Emission: 374.27 kgs
Take Bus from Lentoasema T2 to Rautatientori: Time: 33mins Cost: 6 EUR; $ 7.2 - 8.8 USD CO2 Emission: 0.6 kgs

Source: Rome2rio

Mode of travel comparision chart

The best and cheapest way to get from Lisbon and Helsinki is to travel by air, which will cost about 193 EUR or 235.80 USD.